Hydropneumatic liquid raising plant



Nofir. 26, 1929. O BOVING 1,736,777v I HYDROPNEUMATIC LIQUID RAISING PLANT Filed NOV. 28, 1928 Patented Nov. 26, 1929 UNITED STATES JENS ORTEN BOVING, OF WESTMINSTER, LONDON, ENGLAND HYDROPNEUMATIG LIQUID RAISING PLANT Application filed November 28, 1928, Serial No. 322,332, and in Great Britain November 30, 1927.

This invention relates to hydro-pneumatic liquid raising plants of the kind in which aerated liquid is raised by being drawn up the longer leg of a siphon by means of a par- 5 tial vacuum maintained in and de-aerating the liquid in a closed chamber at the head of the siphon, the de-aerated liquid descending the shorter leg of the siphon, and the partial vacuum being maintained by aspiration by and aeration of a column ofwater descending the longer leg of another siphon.

The invention also involves the use of a hydraulic air compressor and compressed air liquid raising plant of the kind in which a column of water descending under a head due to difference of levels, conveys air to a chamber wherein the air becomes separated from the water and subjected to the pressure head of the water ascending to the lower of the levels, and such compressed air is forced into the lower end of and raises a column of water. As however in the present invention a closed cycle is'employed, a gas other than air may be used.

The object of the invention is to supplement the action of a vacuum liquid raising plant of the above described kind so that in one'stage the liquid can be raised to a considerably higher level than by the vacuum-induced lift alone.

For this purpose, according to the invention, the height of the discharge above the liquid level at the intake of a vacuum-operated aerated liquid-raising siphon of the above described type is arranged to be greater than that to which the vacuum alone can raise the aerated liquid and the lower portion of the lift of the aerated liquid is effected by the introduction into the liquid of air or other gas under pressure,'derive d from a gas-sep arating chamber to which the descending column of aerated waterin the vacuum-inducing siphon descends beneath the lower level of the operative fall thereof.

In other words, the vacuum gas lift is assisted, by a pressure gaslift, and the compressedgas for operating such-gas lift is obtained by prolonging the descending leg of the vacuum-generatingsiphon to form the downwardly directed shaft of a hydraulic gas compressor of the above described type.

Whereas the vacuum-generating and gascompressing portion of the system and the pressure gas and vacuum gas lift portion thereof deal with different quantitiesand may even deal with different sources of liquid, the same gas circulates in common in the two pertions of the system. As, however, there may be incomplete separation of gas and liquid in the vacuum chamber, at the head of the vacuum lift and also. in the separator at the bottom of they compressor shaft, and as some of the gas will be absorbedby the liquid, it will be necessary to supply a certain amount 05 of fresh gas to the system. Such fresh gas can be admitted either to the vacuum chamber or, and preferably, drawn into the ascending leg of the pressure gas and vacuum gas lift at a point where the pressure therein 70 is only slightly below atmospheric pressure. This additional gas will assist the action of the pressure gas and vacuum gas lift.

A representative embodiment of a liquid raising plant according to the invention is illustrated diagrammatically in sectional elevation on the accompanying drawing, in which 'a is the upper water level onone side of a fall and b is the lower water level at the other side thereof.

c is the shorter leg of a siphon which the water ascends to descend the'thelonger leg (Z which is extended by a downwardly directed shaft 6 to beneath the lower level I), to which level 6 the water ascends by an 'upwardly directed shaft g are a series of nozzles drawing in air located at the top of the longer siphon leg (1 by means of which air is drawn into the water descending such leg (Z and the downwardly directed shaft 6. The air thus drawn in is compressed at the bottom of the shaft 6 to a pressure equal to the head of water'in the upwardly directed shaft f.

h is a chamber at the bottom of the shafts e f and in which'the compressed air separates from the water. T

z is the longer leg of avacuum waterraising'siphon dipping into the water at the upper level a. j is the shorter delivery leg of such siphon. k is a chamber at the head of the water-raising siphon i j, in which chamber is a partial vacuum is maintained by such chamber being connected by a pipe Z to the above mentioned nozzles g in the descending legal of the siphon c d.

Compressed air from the air-separating chamber h is supplied through a pipe m, controlled by a cock n to air-injecting nozzles which inject the air into the lower end of the leg 71 of the water-raising siphon, whereby the water therein is aerated and driven upwards. by the expanding air to above the level a. From the height at which the air has expanded to atmospheric pressure, the water is raised by the suction exerted by the partial vacuum in the chamber 72, wherein the expanded air separates from the water, to become drawn in by the nozzles g in the vacuum'indu'cing siphon 0 (Z.

The water freed from air descends the leg of the water-raisingsiphon and discharges at level considerably above the level a from which it was raised;

9 are nozzles on the ascending longer leg 2' of the water-raising siphon at the level where the pressure is slightly below atmospheric pressure,whereby air is drawn from the atmosphere to make up for air carried away in solution or suspension in the water.

'i" are'valve-coiitrolled interconniiunication priming passages for starting the vacuuminducing siphon 0' (Z in the well known manner;

One of the main losses in eiiiciency in separate hydro-pneumatic plants of the types described arises in the entraining 0r forcing in of the air into the water. Consequently by the above described arrangement, in addition to the considerably increased height to which the liquid is lifted, the efficiency of the entire plant is considerably increased owing to the gas iIilet for the vacuum generator serving conjo'intly for the compressor, and the gas injector 0 for the pressure gas lift serving c onjointly as the aerator for the vacuum gas lift, ignoring the small supplementary inlet of gas if admitted to the aseeuding leg of the latter, as at Q. 7 i There are other advantages to be derived from the above described combination as compared with either a plant consisting of a siphonvacuum' generator and a vacuum lift, or a hydraulic air compressor of the type described and a pressure air lift. The lift obtainable with a vacu'liin air lift is obious'ly limited by the practical possible vacuum obtainable, whilst although with such a hydraulic air "compressor the pressure and lift can be increased by deeperexcavation into the ground, deep excavations are expensive and in water-logged areas may be impossible; By the combination of both types of plant, moderately high lifts can be attained in one stage at comparatively low cost.

WVith a vacuum generating siphon used alone the eiiiciency decreases considerably if the water level at the bottom of the longer downwardly directed leg rises to increase the submergence of the outlet thereof, as the air prior to escaping becenies' compressed by the head due to the depth of submergence. Likewisewhen the water levelat the inlet of a hydraulic compressor of the described type used alone rises, the efficiency diminishes unless by cumbersonie that or hand controlled mechanism the inlet is correspondingly raised. Now, as any variation in the upper level of a fall is generally accompanied by a similar variation in the lower level, with the combined vacuum generator and compressor and pressure gas and vacuum gas lift, any

reduction or increase in the vacuum due to compressor is independent of changes in the' upper level;

As usual the ascending leg 11 of the vacuum gas lift is carried to a greater height within the vacuum chamber, than the descending or delivery leg j thereof. Also the introduction of compressed air into the ascending leg 2' is effected at a level sufficiently beneath the lower level a from which the liquidis raised, for the pressure due to the head of liquid to be but slightly less than the pressure of the introduced compressed gas, so as to avoid loss of energy by excessive initial expansion of the gas, and to enable the aerated liquid to rise tothe maximum height by the action of the pressure gas lift, from whence it is raised by the vacuum gas lift;

I claim:

1. In a hydro-pneumatic liquid-raising plant, a vacuum-operated liquid-raising siphon having a discharge end located above the liquid level at the intake end at a height greater than that to which the vacuum in said liquid-raising siphon alone can raise said liquid, a vacuum-inducing,siphon having a limb descending to beneath the lower level of the operative fall of said vacuum-inducing siphon, means for drawing gasinto said vacuum-inducing siphon connected totheorown of said liquid raising siphon, a gas-separat ing chamber at the lower end ofsaid descending limb of said vacuum-inducing sipholm an upwardly directed shaft ascending fromsaid separating chamber to the lower level of the operative fall of said va cuum-indiic ing siphon, and gas-injecting means in the lower end of the ascending limb of said liquid-raising siphon connected to said gas-separating chamber.

2. In a hydro-pneumatic liquid-raising plant, a vacuum-operated liquid-raising siphon having a discharge end located above the liquid level at the intake end at a height greater than that to which the vacuum in said liquid-raising siphon alone can raise said liquid, a vacuum-inducing siphon having a limb descending to beneath the lower level of the operative fall of said vacuum-inducing siphon, means for drawing gas into said vacuum-inducing siphon connected to the crown of said liquid-raising siphon, a gas-separating chamber at the lower end of said descending limb of said vacuum-inducing siphon, an upwardly directed shaft ascending from said separating chamber to the lower level of the operative fall of said vacuum-inducing siphon, gasinjecting means in the lower end of the ascending limb of said liquid-raising siphon connected to said gas-separating chamber, and means for drawing gas into the ascending limb of said liquid-raising siphon where the pressuretherein is only slightly below atmospheric pressure.

In testimony whereof I have signed my name to this specification.

JENS ORTEN BOVING. 

